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- PublicationOpen AccessIdentification and differentiation between olive oil from different Al Jouf olive field areas by optical spectroscopic techniques(AIP Publishing, 2022-10-26)Identification and determination of the authenticity of the produced olive oil by potential spectroscopic techniques have become of nutritional importance to human diet. The study of olive oil is significantly important in trade and business due to the commercial fraud that occurs in the associated business. Al Jouf city, which lies in the northern part of the Kingdom of Saudi Arabia, is famous for its production of the finest quality of olive oil in the kingdom. There is a need to develop feasible in situ identification techniques for the recognition of and discrimination between different olive oil products. One main laser spectroscopic technique known for its superiority over other conventional techniques as an elemental analytical tool is laser induced breakdown spectroscopy (LIBS). Inductive couple plasma mass spectrometry is also a well-known conventional technique with very high sensitivity to most of the elements to the range of parts per billion. However, it requires extensive sample preparation and consumes a lot of time. It has been used as a reference technique to validate the results of the LIBS technique. Moreover, phenolic compounds, which are essential in various types of functional food and folk medicine, were investigated using conventional vibrational analytical tools such as Fourier transform infrared spectroscopy.
- PublicationMetadata onlyPreparation methods of different nanomaterials for various potential applications: A review(Elsevier, 2023-02-12)Nanomaterials are an interesting class of materials that include a wide variety of samples with at least one dimension between 1 and 100 nm. Nanomaterials are cornerstones of nanoscience and nanotechnology. Controlling the size, shape, and composition of the nanomaterials is an uphill task and have a profound impact on their performance. Along with potential health and safety risks, producing large quantities of high-quality nanomaterials are challenging and expensive. The synthesis and growth process of nanostructures and nanomaterials is one of the key elements in the utilization of nanomaterials and their applications in several sectors. The morphology and structure of nanomaterials depend also on the method used for synthesis and growth. This review discusses the various nanomaterial synthesis methods which are categorized into two main types bottom-up methods and top-down approaches depending on starting precursors of nanoparticle generation. Both approaches are critically discussed, in addition, the advantages and disadvantages of each technique have been reported. The aforementioned approaches can have a potential technological applications, such as nano-molecular electronics, optoelectronics, sensors, energy storage materials, composite materials, nano-biotechnology, nano-medicine, etc.
- PublicationMetadata onlyDefective cytokinin signaling reprograms lipid and flavonoid gene-to-metabolite networks to mitigate high salinity in Arabidopsis(National Academy of Science, 2021)Cytokinin (CK) in plants regulates both developmental processes and adaptation to environmental stresses. Arabidopsis histidine phosphotransfer ahp2,3,5 and type-B Arabidopsis response regulator arr1,10,12 triple mutants are almost completely defective in CK signaling, and the ahp2,3,5 mutant was reported to be salt tolerant. Here, we demonstrate that the arr1,10,12 mutant is also more tolerant to salt stress than wild-type (WT) plants. A comprehensive metabolite profiling coupled with transcriptome analysis of the ahp2,3,5 and arr1,10,12 mutants was conducted to elucidate the salt tolerance mechanisms mediated by CK signaling. Numerous primary (e.g., sugars, amino acids, and lipids) and secondary (e.g., flavonoids and sterols) metabolites accumulated in these mutants under nonsaline and saline conditions, suggesting that both prestress and poststress accumulations of stress-related metabolites contribute to improved salt tolerance in CK-signaling mutants. Specifically, the levels of sugars (e.g., trehalose and galactinol), amino acids (e.g., branched-chain amino acids and γ-aminobutyric acid), anthocyanins, sterols, and unsaturated triacylglycerols were higher in the mutant plants than in WT plants. Notably, the reprograming of flavonoid and lipid pools was highly coordinated and concomitant with the changes in transcriptional levels, indicating that these metabolic pathways are transcriptionally regulated by CK signaling. The discovery of the regulatory role of CK signaling on membrane lipid reprogramming provides a greater understanding of CK-mediated salt tolerance in plants. This knowledge will contribute to the development of salt-tolerant crops with the ability to withstand salinity as a key driver to ensure global food security in the era of climate crisis.
- PublicationMetadata onlySUPPRESSOR of MAX2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) Negatively Regulate Drought Resistance in Arabidopsis thaliana(Oxford Acadmic, 2022-06-01)Recent investigations in Arabidopsis thaliana suggest that SUPPRESSOR of MORE AXILLARY GROWTH 2 1 (SMAX1) and SMAX1-LIKE2 (SMXL2) are negative regulators of karrikin (KAR) and strigolactone (SL) signaling during plant growth and development, but their functions in drought resistance and related mechanisms of action remain unclear. To understand the roles and mechanisms of SMAX1 and SMXL2 in drought resistance, we investigated the drought-resistance phenotypes and transcriptome profiles of smax1 smxl2 (s1,2) double-mutant plants in response to drought stress. The s1,2 mutant plants showed enhanced drought-resistance and lower leaf water loss when compared with wild-type (WT) plants. Transcriptome comparison of rosette leaves from the s1,2 mutant and the WT under normal and dehydration conditions suggested that the mechanism related to cuticle formation was involved in drought resistance. This possibility was supported by enhanced cuticle formation in the rosette leaves of the s1,2 mutant. We also found that the s1,2 mutant plants were more sensitive to abscisic acid in assays of stomatal closure, cotyledon opening, chlorophyll degradation and growth inhibition, and they showed a higher reactive oxygen species detoxification capacity than WT plants. In addition, the s1,2 mutant plants had longer root hairs and a higher root-to-shoot ratio than the WT plants, suggesting that the mutant had a greater capacity for water absorption than the WT. Taken together, our results indicate that SMAX1 and SMXL2 negatively regulate drought resistance, and disruption of these KAR- and SL-signaling-related genes may therefore provide a novel means for improving crop drought resistance.
- PublicationMetadata onlyFabrication of titanium dioxide/reduced graphene oxide nanofibers for photodegradation of tartrazine dye in aqueous solution(Desalination, 2022-04)Titanium dioxide/reduced graphene oxide composite nanofibers were fabricated by electrospinning technique. The nanofibers have been prepared by optimizing the ratio of reduced graphene oxide (rGO) to titanium dioxide (TiO2). The morphological, structural and optical properties have been studied by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and UV−Vis spectrophotometry. The surface area has been measured using Brunauer–Emmett–Teller method. The photocatalytic efficiency has been detected by the degradation of tartrazine dye under visible light. The results present that the degradation efficiency reaches 92% for the nanocomposite under visible light. However, the degradation efficiency was 10% for TiO2 only. Moreover, the prepared nanofibers have acceptable stability for several times use. The high efficiency of prepared nanofibers is due to the presence of rGO which improves the photocatalytic activity of nanofibers to degradation of harmful pollutant in water.